DESCRIBE CLIMATE? HOW DO WE

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1 HOW DO WE DESCRIBE CLIMATE? To describe climate, geographers start by gathering data about weather. Meteorologists, the scientists who study weather, supply the data by measuring weather conditions like those in the table below: Temperature Precipitation Wind Conditions maximum (highest) daily temperature minimum (lowest) daily temperature wind speed wind direction amount of moisture in the air (relative humidity) amount of precipitation type of precipitation cloud cover (amount and type of clouds) The climate on Earth works as a system. The global climate system, shown in Figure 2.8, is made up of five parts: Earth s surface, the atmosphere, all the water on Earth, all the ice on Earth, and all life on Earth. With energy from the Sun, these parts interact in several ways to produce the climates of different places. Geographers group together places with similar climates into climate regions. climate regions areas of Earth identified as having similar climate characteristics FIGURE 2.8 This diagram shows the global climate system. The Sun s energy powers the climate on Earth. energy arriving from the Sun clouds gases and ash from erupting volcanoes land and air energy leaving Earth precipitation wind snow and ice human activities water runoff air and ice water and air water ocean currents ice water and ice 54 UNIT 1: Physical Patterns in a Changing World

2 READING CLIMATE GRAPHS Climate graphs combine bar and line graphs to show both average monthly temperatures and average monthly precipitation amounts for a place. Geographers use climate graphs to show and analyze climate data. When you read a climate graph, you analyze the data. Look at the climate graph in Figure 2.9. The average monthly temperature is shown by the line graph. The average monthly precipitation is shown by the bar graph Brisbane, Australia FIGURE 2.9 Climate graph for Brisbane, Australia 5 temperature precipitation Climate Data for Brisbane, Australia an Feb Mar Apr May un ul Aug Sept Oct Nov Dec Average monthly temperature ( C) Average monthly precipitation (mm) FIGURE 2.1 Climate data for Brisbane, Australia HOW TO READ A CLIMATE GRAPH Determine the average annual temperature. Using the data in Figure 2.1, add up the monthly temperatures. Divide by 12. Determine the precipitation pattern by looking at when most of the city s precipitation occurs. Most places in the world match one of these three patterns: winter maximum most precipitation occurs in the coldest months of the year summer maximum most precipitation occurs in the warmest months of the year evenly distributed each month has about the same amount of precipitation As you can see, you need to look at both temperature and precipitation to figure out the precipitation pattern. STEP 1 STEP 2 STEP 3 STEP 4 Determine the temperature range. This is the number of degrees from the highest monthly temperature to the lowest. Subtract the lowest monthly temperature from the highest monthly temperature. Determine the total annual precipitation. This is calculated by adding up the monthly precipitation totals. CHAPTER 2: Changing Patterns of Climate 55

3 (hot with dry season) steppe (warm and dry) desert (hot and very dry) GLOBAL CLIMATE PATTERNS mild polar 2.11 This map FIGURE (very cold and dry) shows climate regions around the world and climate graphs for each region. Which mountainous climate region is the least like the climate from where (altitude affects climate) you live? Why do you think it is so different? F M A M A S O N D ARCTIC (very cold winter) Iqaluit (63.75 N, W) White box in bottom layer. Climate Graphs Winnipeg (49.9 N, W) temperature precipitation PACIFIC Winnipeg, Canada Geography 5 7 SB World Climate Regions tropical (hot with rain all year) savannah C2-F4I-G7SB (hot with dry season) Crowle Art Group Belém, Brazil 4 Pass Approved35 3 White box in bottom Not layer.approved (hot and very dry) mild (warm and wet) subarctic (very cold winter) polar (very cold and dry) mountainous (altitude affects climate) Dubai, United Arab Emirates F Geography M A M 7 SB A S O N D X UNITFN 1: Physical Patterns C2-F4A-G7SB in a Changing World CO Crowle Art Group 4 Climate Graphs temperature precipitation F M A M A S O N D 2 4 PACIFIC Tropic of Capricorn continental (dry with cold winter) Lusaka, Zambia Belém (1.45 S, 48.5 W) 4th passdesert 5 Equator steppe (warm and dry) ATLANTIC Tropic of Cancer X F M A M A S O N D FN CO d) G7SB t Group Iqaluit, Canada 3 (warm andregions wet) Climate are found in different parts of the world. continental Geographers group them into nine overall climate regions (dry with cold winter) assubarctic seen here in Figure Antarctic Circle 5

4 Münster, Germany Yakutsk, Russia Arctic Circle Yakutsk (62.3 N, E) White Münster box (51.96 N, in bottom 7.63 E) layer. White box in bottom layer. Mashhad (36.3 N, 59.6 E) Dubai (25.2 N, 55.3 E) Lhasa (29.65 N, 91.1 E) PACIFIC 4F-G7SB Art Group s N Geography 7 SB X FN CO Pass Approved Not Approved C2-F4H-G7SB Crowle Art GroupINDIAN 3rd pass Lusaka (15.41 S, E) A TLANT I C 1 km Mashhad, Iran Lhasa, China CHAPTER 2: Changing Patterns of Climate 57

5 MAKING CLIMATE GRAPHS You already know how to read a climate graph. In this activity, you will learn how to make one. Climate Data for Beijing, China an Feb Mar Apr May un ul Aug Sept Oct Nov Dec Average monthly temperature ( C) Average monthly precipitation (mm) FIGURE 2.12 Climate data for Beijing, China. How might you draw a graph using two sets of numbers and keep them separate on the graph? HOW TO MAKE A CLIMATE GRAPH Draw the x axis for the climate graph on graph paper. Label 12 spaces along the x axis (horizontal) with the initials of the months of the year. STEP 1 STEP 2 Your graph needs two y axes (vertical). Draw the left axis for temperature first. Label the lines from 5 C to 3 C. The temperature labels can be adjusted depending on the highest and lowest temperatures of the place you are graphing. For example, you might start at 2 C if there are no very low temperatures for the place. Label this axis Temperature. Now draw the right y axis for precipitation. Label the lines with mm on the bottom line and intervals of 5 mm to the top. Precipitation labels can also be adjusted, but mm must always be on the bottom line. Label this axis Precipitation. STEP 3 STEP 4 Make a line graph to show temperature. Find the temperature for each month from the data table for Beijing (Figure 2.12). Put a red dot in the middle of each column for each month using the left y axis. Once you have plotted all 12 points, join the dots with a red line. Make a bar graph to show precipitation. Find the precipitation amount for each month from the data table for Beijing. Draw a bar for each month using the right y axis. Colour the bars blue. STEP 5 STEP 6 Add a title above your climate graph, giving the name of the place. 58 UNIT 1: Physical Patterns in a Changing World

6 HOW CLIMATE DATA TELLS US CLIMATE IS CHANGING Climate graphs can help us identify how climate is changing. Comparisons can be made among climate graphs of the same locations over periods of 1, 2, or more years. In many parts of the world, detailed climate statistics have been kept for over 1 years (Figure 2.13). Changes in temperature and precipitation trends are good indicators of climate change. These are some aspects to compare: ly temperatures: Changes to the hottest and coldest monthly temperatures tell us whether there is a warming or cooling trend. Temperature ranges: Changes to the temperature range tell us whether the range is becoming larger, with hotter summers and colder winters, or whether the range is becoming smaller, with cooler summers and warmer winters. Precipitation totals: Changes to precipitation totals tell us whether there is more or less precipitation. Precipitation patterns: Changes to precipitation patterns tell us whether there are drier summers or wetter winters. Comparing climate graphs for just one location will not give us a very good understanding of the ways that the climate is changing around the world. Geographers will compare climate graphs over a wide area and over long periods of time to create a detailed understanding of the changing climate. What can precipitation patterns tell us about the climate of a particular place? Temperature change from average ( C) Global Temperature Changes, Years FIGURE 2.13 This graph shows changes in temperature from 185 to 212. CHECK-IN 1. INTERRELATIONSHIPS Review Figure 2.8 on page 54 and explain the global climate system to a partner in your own words. 2. GATHER AND ORGANIZE Choose one of the climate regions from Figure 2.11 on pages 56 and 57. Find more information about that climate type and places in the world with that climate type. Decide on an appropriate way to share your information. 3. PATTERNS AND TRENDS Figure 2.11 shows the climate regions around the world. Study the map and think about what you know about the natural environment. Using your prior knowledge, predict three factors or forces that might create the patterns shown on the map. CHAPTER 2: Changing Patterns of Climate 59